The present invention relates to a friction stir welding apparatus, and more particularly relates to a friction stir welding apparatus having a probe detection mechanism, a processing-member detection mechanism, and a probe cleaning mechanism.
In recent years, there has been proposed a friction stir welding apparatus that performs friction stirring on a predetermined welding portion in a processing target component formed by a plurality of metal plates such as aluminum plates by a probe rotating at a high speed, in addition to general arc welding, to weld the metal plates with each other. Even in a strength component of a movable body such as an automobile, a configuration having a welding portion welded by a friction stir welding apparatus has been realized.
In such a friction stir welding apparatus, the rotating probe and the processing target component need to be moved relative to each other to weld a predetermined welding portion accurately. Accordingly, it is important to execute friction stir welding by detecting parameters required therefor with high accuracy, taking the detection values thereof into consideration.
Under such circumstances, although it is not related to a friction stir welding apparatus, Japanese Patent Application Laid-open Publication No. 2002-283059 discloses setting of a shaft reference position of a servo spot welding gun and a robot control apparatus therefor. The robot control apparatus has such a configuration that a movable welding tip of the welding gun is pressed against a fixed welding tip until an estimated disturbance load reaches a set first threshold, and when the estimated disturbance load has reached the first threshold, the movable welding tip is driven in a direction in which the both tips are away from each other until the estimated disturbance load reaches a second threshold smaller than the first threshold, to set, update, and store the shaft position of the movable welding tip when the second threshold is reached as a reference position, thereby enabling to obtain and update the reference position in the same manner even when the welding tip is worn off.
Japanese Patent Application Laid-open Publication No. 2007-30017 relates to a friction stirring welding method and discloses a configuration in which after a rotation jig is moved to a temporary setting position determined based on deflection amount data of a support table generated when a welding pressure is applied and thickness data of an overlapped portion, position control of a servo motor is canceled at the temporary setting position and torque of the servo motor is controlled. After a certain time has passed since the start of torque control, a moving distance of the rotation jig is measured, to obtain a welding operation start position based on the obtained moving distance and the temporary setting position, and then a friction stir welding operation with respect to the overlapped portion is performed by using the welding operation start position as a reference.
Japanese Patent Application Laid-open Publication No. H5-138361 relates to a nozzle cleaning apparatus of a welding torch, although it is not related to a friction stir welding apparatus. The nozzle cleaning apparatus includes a pre-processing device 10 in which a plurality of long wires 12 having a tip bent inward and a plurality of short wires 13 having a tip formed in an outward hook shape are erected on a circumference slightly smaller than an opening end diameter of a nozzle 7 of a fixed table 11, and a main processing device 20 in which a plurality of long brushing bars 22 and short brushing bars 23 having fine wires implanted at the end thereof are erected on a circumference slightly smaller than the opening end diameter of the nozzle 7 of a turntable 21 and a cylindrical wire brush 24 is provided in a standing condition outside thereof, thereby eliminating spatters near a gas outlet 9 and circular spatters at the opening end of the nozzle 7.